1. Field of the Invention
The present invention relates to a child seat, in which a seat unit is placed on a base unit to be fixed to a seat of a vehicle in a reclinable manner.
2. Description of the Related Art
Several classes are defined in a child seat according to the weight of a child (including an infant). For example, in conformity with ECE R44/03 applied in Europe, child seats for children within a range from about nine months or elder to about twelve years old or younger are classified into three classes according to weights: G1 (9 kg to 18 kg), G2 (15 kg to 25 kg) and G3 (22 kg to 36 kg). In addition to these classes, a G0 class is provided for a child of 0 to 18 months or having a weight of about 3 kg to about 13 kg. The child seats are variously configured according to the classes. For example, as for a sitting attitude, a baby cannot sit forward on a seat of a vehicle in a baby seat of the G0 class; a child can sit forward on a child seat of the G1 class; and a child can sit only forward in child seats of the G2 and G3 classes. From the viewpoint of a restraining manner of a baby or a child, the baby or the child is restrained on a seat unit by using a special restraining belt in the child seats of the G0 and G1 classes; and the child is restrained by using a seat belt of the vehicle in the child seats of the G2 and G3 classes. In addition, there are various differences according to the classes.
However, a burden is exerted on a user to buy the baby seat and the child seats according to the classes. Furthermore, a product may be discarded with wastage irrespective of the sufficient remainder of the lifetime of the product. In view of this, there has been proposed a child seat which can be used in any of a plurality of classes by changing usage modes.
There has been proposed a child seat which can be used in both of, for example, the G0 and G1 classes, the child seat comprising a base unit fixable to a seat of a vehicle by using a seat belt of the vehicle or a special fixing tool and a seat unit fixed onto the base unit in a manner turnable about a turning axis in a vertical direction. In the child seat of this type, a baby is restrained by a special restraining belt in a laying attitude by setting the seat unit rearward at the time of use as a seat of the G0 class; in contrast, a child is restrained in a sitting attitude by a restraining belt by setting the seat unit forward at the time of use as a seat of the G1 class.
Alternatively, there has been proposed an auxiliary child seat which does not have a restraining belt but is provided with a seat cushion portion and a seat back portion which can be detached from each other, wherein a child sitting position is corrected so as to be suited for a seat belt of a vehicle, or a seat belt of a vehicle is guided to be adapted to a child. In the child seat of this type, the seat cushion portion and the seat back portion are placed on a seat in combination at the time of use as a child seat of the G2 class; in contrast, the seat back portion is detached from the seat cushion portion, and then, only the seat cushion portion as a so-called booster is laid under a child at the time of use as a child seat of the G3 class. The above-described child seat has been developed to provide a child seat which can be used also as a child seat of the G1 class by disposing a shield in front of a child and restraining the shield by a shoulder belt portion of the vehicle. Although the seat of this type may be called a junior seat, it is included in modes of the child seat in the present specification.
The conventional child seat to be used commonly in the G0 class and the G1 class has a shell structure in which a seat unit is formed by integrating a seat cushion and a seat back with each other. Moreover, since a child is restrained by a restraining belt dedicated to a child, a cabin in the child seat is liable to be small for a well-built child, and therefore, the above-described child seat cannot cope with the child seats of the G2 class or more. Additionally, since the seat unit is configured in the shell structure, the inclination angle of the seat back with respect to the seat cushion is not varied even if the seat unit is reclined with respect to the base unit. Consequently, when the seat back is reclined in a horizontal direction, the seat cushion is inclined up forward, and as a result, the child may be forced to sprawl his or her legs upward in an unnatural attitude.
In the meantime, in a child seat in which a child is restrained by using a seat belt of a vehicle, a cabin can be largely secured. Since a seat back is turned with respect to a seat cushion, the inclination of the seat cushion is not varied even if the angle of the seat back is adjusted in accordance with an appropriate value, and therefore, a child sitting on a seat cannot be forced to take an unnatural attitude. However, a relatively large shield is placed in front of a child at the time of use as a child seat of the G1 class, thereby degrading conformability in comparison with the case of the use of the special restraining belt.